Arrhythmia is a variation from the normal rhythm of the heart beat. The major cause of fatalities due to cardiac arrhythmias is the subtype of arrhythmias known as ventricular fibrillation. Conservative estimates indicate that, in the U.S. alone, approximately 300,000 individuals per year suffer heart attacks. Approximately half of these die from sudden cardiac death, the major cause of which is ventricular fibrillation.
Antiarrhythmic agents have been developed to prevent or alleviate cardiac arrhythmia. For example, Class I antiarrhythmic compounds have been used to treat supraventricular arrhythmias and ventricular arrhythmias. Treatment of ventricular arrhythmia is very important since such an arrhythmia, especially ventricular fibrillation, can be fatal. Serious ventricular arrhythmias (ventricular tachycardia and ventricular fibrillation) occur most often in the presence of myocardial ischemia and/or infarction. Ventricular fibrillation often occurs in the setting of acute myocardial ischemia, before infarction fully develops. At present, lidocaine is the current drug of choice for prevention of ventricular fibrillation during acute ischemia. However, many Class I antiarrhythmic compounds may actually increase mortality in patients who have had a myocardial infarction. Therefore, there is a need in the art to identify new antiarrhythmic treatments, particularly treatments for ventricular arrhythmias (as discussed above), as well as for atrial arrhythmias, which are also lacking suitable medical treatment. The present invention fulfills this need, and further provides other related advantages.